Assessing chronic stress in wild mammals using claw-derived cortisol: a validation using European badgers (Meles meles).

Measuring stress experienced by wild mammals is increasingly important in the context of human-induced rapid environmental change and initiatives to mitigate human-wildlife conflicts. Glucocorticoids (GC), such as cortisol, mediate responses by promoting physiological adjustments during environmental perturbations. Measuring cortisol is a popular technique; however, this often reveals only recent short-term stress such as that incurred by restraining the animal to sample blood, corrupting the veracity of this approach. Here we present a protocol using claw cortisol, compared with hair cortisol, as a long-term stress bio-indicator, which circumvents this constraint, where claw tissue archives the individual's GC concentration over preceding weeks. We then correlate our findings against detailed knowledge of European badger life history stressors. Based on a solid-phase extraction method, we assessed how claw cortisol concentrations related to season and badger sex, age and body-condition using a combination of generalized linear mixed models (GLMM) (n = 668 samples from 273 unique individuals) followed by finer scale mixed models for repeated measures (MMRM) (n = 152 re-captured individuals). Claw and hair cortisol assays achieved high accuracy, precision and repeatability, with similar sensitivity. The top GLMM model for claw cortisol included age, sex, season and the sex*season interaction. Overall, claw cortisol levels were significantly higher among males than females, but strongly influenced by season, where females had higher levels than males in autumn. The top fine scale MMRM model included sex, age and body condition, with claw cortisol significantly higher in males, older and thinner individuals. Hair cortisol was more variable than claw; nevertheless, there was a positive correlation after removing 34 outliers. We discuss strong support for these stress-related claw cortisol patterns from previous studies of badger biology. Given the potential of this technique, we conclude that it has broad application in conservation biology.

Pilot study to assess the use of a fluorescence imaging system for assessment of amputation healing.

OBJECTIVE:: The purpose of this study was to use a fluorescence imaging system (FIS) (SPYElite, NOVADAQ, US) during lower extremity amputations and develop parameters to predict amputation healing, for which there are no proven, objective tests. We hypothesised that the FIS may identify areas of poor perfusion at the time of amputation and predict potential healing complications. There are no studies involving the FIS used in this study in lower extremity amputation. METHOD:: This prospective cohort study involved patients requiring either below- or above-knee-amputation at one, mid-western medical centre. The FIS was used as per manufacturer's instructions after wound closure and before dressing. Procedure and operative management was unchanged. Through the FIS, perfusion values were plotted along the amputation site to visualise and quantify intraoperative perfusion and to compare with 30-day postoperative amputation healing. RESULTS:: Surgeons determined that all of the 18 participants had adequate perfusion at surgical wound closure. At 30 days, two subjects had wound dehiscence or infection; these correlated with low perfusion values on the FIS imaging. A further six subjects had marginal or low perfusion values, but did not develop wound failure. CONCLUSION:: It is feasible to use the FIS during amputation, however it did not perfectly predict healing course based on vascular perfusion. There were interesting patterns of poor perfusion that correlated with areas of dehiscence or infection but other patients had reduced perfusion that healed well. Due to the small sample size, no discernible perfusion value differences existed between patients who healed and patients with healing complications. A future, larger study may show that the FIS can be predictive of patient healing and aid decisions for intraoperative revision.

Patient Body Mass Index and Physician Radiation Dose During Coronary Angiography.

BACKGROUND: Consistent with the increasing prevalence of obesity in the general population, obesity has become more prevalent among patients undergoing cardiac catheterization. This study evaluated the association between patient body mass index (BMI) and physician radiation dose during coronary angiography. METHODS AND RESULTS: Real-time radiation exposure data were collected during consecutive coronary angiography procedures. Patient radiation dose was estimated using dose area product. Physician radiation dose in each case was recorded by a dosimeter worn by the physician and is reported as the personal dose equivalent (Hp10). Patient BMI was categorized as <25.0, 25.0 to 29.9, 30.0 to 34.9, 35.0 to 39.9, and ≥40. Among 1119 coronary angiography procedures, significant increases in dose area product and physician radiation dose were observed across increasing patient BMI categories ( P<0.001). Compared with a BMI <25, a patient BMI ≥40 was associated with a 2.1-fold increase in patient radiation dose (dose area product, 91.8 [59.6-149.2] versus 44.5 [25.7-70.3] Gy×cm2; P<0.001) and a 7.0-fold increase in physician radiation dose (1.4 [0.2-7.1] versus 0.2 [0.0-2.9] µSv; P<0.001). By multiple regression analysis, patient BMI remained independently associated with physician radiation dose (dose increase, 5.2% per unit increase in BMI; 95% CI, 3.0%-7.5%; P<0.0001). CONCLUSIONS: Among coronary angiography procedures, increasing patient BMI was associated with a significant increase in physician radiation dose. Additional studies are needed to determine whether patient obesity might have adverse effects on physicians, in the form of increased radiation doses during coronary angiography.

Impact of patient obesity on radiation doses received by scrub technologists during coronary angiography.

BACKGROUND: The impact of patient obesity on scrub technologist radiation dose during coronary angiography has not been adequately studied. METHODS: Real-time radiation exposure data were prospectively collected during consecutive coronary angiography cases. Patient radiation dose was estimated by dose area product (DAP). Technologist radiation dose was recorded by a dosimeter as the personal dose equivalent (Hp (10)). Patients were categorized according to their body mass index (BMI): <25.0, lean; 25.0-29.9, overweight; ≥30.0, obese. The study had two phases: in Phase I (N = 351) standard radiation protection measures were used; and in Phase II (N = 268) standard radiation protection measures were combined with an accessory lead shield placed between the technologist and patient. RESULTS: In 619 consecutive coronary angiography procedures, significant increases in patient and technologist radiation doses were observed across increasing patient BMI categories (p < 0.001 for both). Compared to lean patients, patient obesity was associated with a 1.7-fold increase in DAP (73.0 [52.7, 127.5] mGy × cm2 vs 43.6 [25.1, 65.7] mGy × cm2, p < 0.001) and a 1.8-fold increase in technologist radiation dose (1.1 [0.3, 2.7] µSv vs 0.6 [0.1, 1.6] µSv, p < 0.001). Compared to Phase I, use of an accessory lead shield in Phase II was associated with a 62.5% reduction in technologist radiation dose when used in obese patients (p < 0.001). CONCLUSIONS: During coronary angiography procedures, patient obesity was associated with a significant increase in scrub technologist radiation dose. This increase in technologist radiation dose in obese patients may be mitigated by use of an accessory lead shield.